Measured-service telephone system



Dee. 2-1". 192

B. D. WILLIS MEASURE-D SERVICE TELEPHONE sYs'i'EM ori inal Filed Now-17. 1920 2 Sheets-Sheet 1 B. D. WILLIS MEASURE-D SERVICE TELEPHONE SYSTEM Original Filed Nm}. 1?, 1920 -2 Sheet-Sheet 2 Emmi- B nard'Dlnf I15 Patented-Dec. 21', 1925. I

V BERNARD-.0. WILLIS, or bar; PARK,

rare T AUTOMATIC ELECTRIC INC, OF CHICAGO, ILLElliOIS, A CORPORATION 01 DELA- WARE.

Applicationfiled November 7, iezc serial No. 424,747.

Ihe present invention relates in generalto 'measured servicetelephone systems, but

more particularly to automatic party line measured service. systems, and the principal 5 objectof the invention is the provision of a system of thiskind ',a' party line is provided with a meterlat the exchange, and wherein eachmeter is adapted to'be separately connected for registering calls whenever its associated station is calling; f

The novel feature ofthe invention lies in the method of controlling 'the meter selection, in which a calling subscriber selects 'form in order to initiate the call.

The means" by which the foregoing is accomplished will be described fully hereinafter, reference being had to the accompanying d'rawings, in which Fig. 1' shows the preferredform of different apparatus at the exchange.

Referring first to Fig. 1, this is a" circuit diagram of; the usual form ,whichshows sufficient of the apparatus in an automatic telephone system to enablethe inventionto be explained and understood. More specifically, thedra wing shows a two party line comprising conductors 11 and 12 and-having automatic telephonesubstations A and whose functi on The individual llnefsw toh C which is assooiated with the party line at the exchange is of the well known plunger type, and togeth'er with a plurality gotsimilar line,

D. The' selector' and connectorv wherein each station on this-meter for operation in the course of a preliminary act which he is required to per- .tions on a party the invention, while Fig." 2 is a modification operating on the same; 7 general principles, but employing somewhat I stations on the and 12, respectively,

line telephones Aand A' is also pro- MEAsUnnD:snnvrcn Tanner-ions sYsTnM.

Rtne wed May 22,1926.

switches is controlled in its trunk selecting operations by means of the master switch switches E and Hare or thef'well' known Strowger vertical and rotary type asregards their'mechanical construction and areoperated ac-' cording to the two wire system of control. Line, selector, and connectorswitchesof the type mentioned are well known and are fully shown and described 'intl e book entitled Automatic Telephony, Smith and Campbell, published by the McGraw-Hill Book Company in 1914. v V f vThe meters Ma'nd M are associatedwith substations and At, respectively, and may be located at any suitable point in the exchange. In "order to selecttheprop'er meter for operation when one of the staline is calling", certain additional relays-are provldedin the 'line switch O, and in this respect the circuit of the line-switch difi'ersfrom theone ordi-' mmnoisessisnorv, BY lvinsnnasslenianncrs, 1

narily use'di Otherwise, however, the line switch is of the ordinary construction.

he apparatus involved having been briefly d escribed,- its operation will: now beexp-lained somewhat more indetail, with a view to pointingyout how the proper meter at the exchange is operated whenever one of" the 1 party line establishes a successful connection; For thislpurpose 1t w1ll :be assumed thatthe subscriber at substation A desires toobtain a connection with-the subscriber atsubstation A I Then the re ceiver isremoved the calling. device, transmitter,: and receiver are bridged across the I line in the usual manner, but'contrary to. the usual practice .nothinghappens. at the exchange, for the two line relays 13 and 14' which are associated with lineconductors 11 are both connected to the ungrounded pole of the exchange 'battery. The subscriber at substation A, theretore, isirequired toiper'form some other not before heican operatethe line switch-.0 and obtain access to a first selector switch. and

,this act consists in momentarily depressing the push button; 1?. which. is conveniently lohisft'elephone instrument ":W'hen cated on the push button P is operated across the, line cnductors lifaiidfflZjis v v i opened and ground is connected to the lower line conductor 11 thereby completing a circuit which'includes the said line conductor, the normally closed cut-off springs 29 and 28 at the line switch C, and the winding of the line relay 13' to battery. Upon energizing,relay 13 closes a circuit at its armature 18 for the slow acting relay 16 which is accordingly energized also. Push button 1 need be depressed only for an instant and when it is released ground is disconnected from line conductor 11 and the circuit of relay 13 is broken. This relay, therefore, de energizes and breaks the circuit of relay 16, but since the latter relay is slow acting it will not fall back immediately and a circuit is momentarily completed through the pull in winding 31 of the line switch as follows: from groundby way of resting contact of armature 19 and the said armature, working contact of armature 22 and the said armature, pull in winding 31 and through a normally closed contact at the master switch D to battery. Upon energizing, the pull in winding attracts both the cutoff armature 83' and the plunger arm 34, the former being 0perated to disconnectthe line conductors 11 and 12 from the'windings of the line relays 13 and 14, respectively, while the latter forces the bank springs 40, 41,42, and 43 into en gagen ent with contacts 44, 45, 46, and 47, respectively. By the engagement of bank springs 40 and 43 with contacts 44and 47,the line conductors ll and 12 are extended into engagement with the trunk line conductors 48 and 50 which terminate in the windings of the line relay (not shown) of the selector E. The line and release relays in the selector are therefore energized, and the latter relay connects ground to the release trunk conductor 49. Bank spring'41 being now .in engagement with contact 45, a holding circuit is thusestablished for the holding winding 32 otthe line switch C which is thus energized in order to maintain the cutoil? armature 33 and the plunger arm 34 in This holding circuit is established before the slow acting relay 16 has had time to all back. In addition to the function explained, the holding circuit also serves to maintain ground potential on the private normal conductor 10 which eX- tends to multiply connected test contacts in the banks of the connector switches which have access tothe party'line, thus guarding the line against intrusion in the customary manner. Another circuit closed by the operation of the line switch is completed by the engagement of bankspring 42 with contact 46; VJhen this contact is closed the operating magnet of the meter M is connected in 'se-f ries over conductor 23 with the left hand winding of relay 52, and the latter relay is energized, being of such high resistance, however, that the meter M is prevented from trunk conductors.

operating. Upon attracting its armature 55, relay 52 extends ground to the test contact associated'with the selected trunk line in the test bank of the master switch 1), whereby the said master switch is operated and the plungers of all the other idle line switches in the ron are advanced into association with a V I an idle trunk line. 1

The foregoing operations have occurred in response to the removal of the receiver at substation A and the actuation of the push his calling device in accordance with the dig itsin the telephone number assigned to substation A and as a result the selector E and a connector switch, wh ch we will assume is the connector H, are operated" in thewell known manner to establish connection with the called line and signal the called subscriber. These operations are well known and need not be explained in detail herein.

It will be sufficient to say that when the selector E is operated and connects with the connector hi, the trunk line. conductors 48 and 50 are extended through to'the windings of the line relay 71, which thereafter controls the operation of the connector switch. This relay also maintains a circuit for the slow acting release relay 72, which in operation maintains ground on the release trunk con- 'ductor 49, which extended through to the connector at the same time as line conductors 4S and 50.

When the called party at substation A answers by removing his receiver a circuit is completed for, the double wound back bridge relay 70, which upon energizing reverses th'e trunkconductors 48 and 50 as regards their connection to thewinc'lings of the double wound line relay 71, and therefore reverses the direction of current flow in these This brings us to consideration of the means 01 actuating the meter M to register the call. T he relay 51 in the trunk line eX- tending to the selector E is an electropolarized relay which has a polarizing'winding of high resistance and few turns through which current flows from the groundedre'lease conductor 49 while the-trunk line is in use. This winding and the right hand winding,

which is in series with conductor 48, are in,

opposition during the establishment of the operative.

connection and until the called subscriber answers, relay '51 therefore remaining 111-.

Vhen the called subscriber fair" swers, and current is reversed in the trunk li niai'ntained in operated position its. left hand winding alone, and the right hand winding issh'ort circuited at armatureu53 inorder not to lnterfe'rie with thetallnngcir- 'cuit. f At its armaturefiel; relay 51 connects --the low resistancev right hand winding of rea. lay 52 in parallel with-.the left hand winding 4 Ofthe saidrelay. and bylthis operation the current 'flow-in the circuit; of the operatinginagnet of the ineter' Mis sufiiciently in creased'to'cause the said magnet to energize.

call. a V a Conversationmay now proceed over the established talking circuit in the customary manner-Q Since relay 51;i s held up ground "on the release trunk conductor 49 independ- .is released. i a, V 1

. Having explained how the nieter M; is opcra-tedwhen a call is niadefroin. substation A, the process of operat-ingtne meter 1M The'n'ieter M is thus operatedto register the ent-o'tthe called subscriber no further operation of, the; meter can take place. ,iVheri'the subscribers are through talking they will hang up their receivers, and theconnection when afcall is made from substation A may ,now be 'briefiy described h Before proceed;

'ng it will be advisable to consider the wiring ofthe push buttons at the two subs-ta tions, as these push buttons determine the selection of the proper meters at the 8X1 change Push button P at substation A wexactlylike the push button P at substation A, and isfconnected in the telephonecircuit in thesame way. In the case of substation A choweverthe break contacts at the push button areshort circuitechsothat whenever thepush button is'oper'ated both of the line aconductors will be grounded, instead of only thelower line conductor 11. I

Suppose now that a subscriber at substa-.

I tion A, desiresto make a call. The receiver first removed, butwithout result, as ex- Tit);

'. plained'in the previousicase; The subscriba er will now operate tliejpush buttonP for an instant, thereby grounding both of the t line conductors 11 and 12. As aresult rej [lays 13 and14 of the individual line switch. C are energized and the former relayI'clos-es a circuit for the slow acting relay 16, which energizes and prepares. a circuitfor the pull in winding 31. Relay 14:, upon energizing, closes a icircuitfor the slow acting relay 15 at its armature 17, and when the latter relay pulls up it prepares a lockinglcircuitforit self at its armature 20, and at its arniatureQ-I 1 shifts ther'neter controljwire2 3iinto 60111196 tion with the operating Inagnet'of meter: M When the push button at substationA is re'-. leased ground removed from the line conductors and relays 13 and let will fall back and breakthe'circuitsof relays 16 and 15, respectively; I slow acting, however, ancLbefore'theyrhave' time to deenergize the line switch C is'op-' Boththe ,latter yrelays are way of bank contact 45,, bank springs 41',

Iconta'ct springs 25 and 24, armature 20 and its work ng contact, and the winding of re lay 15 to battery. Relay'15'will therefore ,be held energized throughoutthe duration of, the connection. v 7 Operations which take place in'establishing The remainder of the the desired connection are similar to those already described and need'not berepeated.v It will be evident that when the called sub- 7 jscriher answers 'andfthe' polar relay. 51' in the first selector trunlris operated, the meter M frather than-the nieterM will be actuated to register the call. V v Y, 1 r

The niod'ficationotthe invention which is shown in F ig. 2 will now be explained; In thisfigure a party lineis shown whichcorhprises the line conductors 1111 and112fa'nd eratedas explained hereintofore toestablish 7' connection with an idle trunk l1ne,%wh1ch the telephone substations Atand A. "At the .eXch'ange the party line-isprovided with the two phingertype line switches C and (3*, thusdifi'ering in an e'ssentialrespect froin the party lineshown i'n Fig. 1 which is "only 'providedwith a single line switch. The remaind er of the apparatus however, compris ing the" trunk relays 151 and 152, theselector E, and the connector 11-1 is the same as shown in thei other d awing. l Meters M and M are associated with substations-A? and Aflrespectively. I t

Eachfo fthe telephone substationsiis providedfwith apush butt0n,the'se pushbub tons being indicated I the reference character's P?" and P",- respectively. The wiring at, both telephones, including the wiring of 5 ,thepush buttons, is exactly the" same, and

the selection of the ineters fat the exchange is controlled a reversal in the line between the two stations. i

; Proceeding'now with the explanation of the circuit operations, suppose that the subscriber, at substation A desires to call a sub- [scriber at substation A The receiver is first removed, land the subscriber will now Toperate the push button P for an instant.

As aire sult ground'is placed upon line conclu'cto'r 111" and a circuit isl'coinpleted which extends by way of the saidiline conductor "111; through the normally closed. cut-off springs and 121 of linejswitch 0 nor- -mally closedcuuofi springsj122 and 123of y l neswitch C2 and the winding of relay 113 tobatteryi Relay 113 is accordingly e'nere gized and establishesa circuit for :the relay 114., which energiz e's inturn -and prepares a circuit for the pull in winding 115 of the line 115, thefline switch C is operated in the usual manner to, extend the calling party line intoconnection' withan idle trunk line,

which will be assumed to be the trunk line extending to the selector E. r The line and release relays of the selector are then energized over the line circuit, and the latter relay places, ground upon release trunk conductor 1 19, thereby establishing a holding circuit for the holding or cut-off winding 116 of the line switch C These operations, and the remaining operat ons by which the calling line is extended into connection with a desired called line are similar to the corre sponding operations which have been describedin connection with Fig. 1, and therefore will not be considered in further detail. It will be suflicient to state that when the called subscriber answers, the electropolarized relay 151 in the selector trunk is operated and connects the right hand winding of the double wound relay 152 in parallel with the left hand Winding of the said relay. This increases the flow of current in the previously established meter control circuit, in-

cluding the operating magnet of meter M and said meter is accordingly actuated to quirmg the subscriber at each station to acregister the call.

When the subscriber atv substation A makes a call the operations are just the same as those described, except that when the push button P is depressed line conductor 112 will be grounded, instead of the line conductor 111. As a result a circuit is completed fo-r'the line relay 133 of line switch G which extends by way of the said conductor 112, cut-off springs 12 1 and 125. of. line switch C cut-ofl' springs 126'and 127 of line switch C and the winding of the line relay 133 to battery. Relay 133 is, therefore, energized and closes the circuit of relay 134, and these two relays operate jointly \Vhenthe push button P is released at the substation to bring about the energization ot' the pull in winding 13; of line switch C.

- Thus it will be seen that when the subscriber at substation A makes a call the line switch C will be used rather than the line switch C and it will be evident then that meter M will be connected for use and will T be operated to register the call when the called subscriber answers.

Hav ng descrlbedmy nvention, what I consider to be new and desire to have tected by Letters Patent will be pointed out in the appended claims. 1

Vhat I claim as my invention is:

1. In a telephone system, a party line, ameter at the exchange for each station on' prothe line, a push button at each of'said stations, line extending switching mechanism at the exchange responsive to the operation.

of the push button at a callin station, and mechanism controlled in accordance with the push button which is operated for selecting the proper meter to register the call.

2. In a telephone system, a party line, switching mechanism at the exchangefor extending the line when calling, a push buttonat each station on the line. for operating said mechanism, a meter at the exchange for each of said stations, and means controlled by the push button which is actuated when a call is made for determiningwhich of said 7 meters will be operated to register the call.

3. In a telephone system, a party line,

switching mechanism at the exchange for extending the line when calling, a push button at each'station on the line for operating said mechanism, a meter at the exchange for each 01" said stations, a relay for determinin'g which of said meters will be operated when either station makes a call, and means for operating said relay only when the push button at a particular station is actuated.

1. In a telephone system, a two party line, a switching device at each station on the line, the device at one station being-adapted to ground both sides of the line while the device at the other station is adapted to ground one side only, a meter at the exchange for each of'said stations, means re .strumentalitiesiofaa station are placed in talking condition to make a call, and means line, thedevice at one station being adapted to ground both sides of the line while the device at the other station is adapted to' ground one side only, after a call has been initiated from the respective stations, a meter at'the exchange for each of said stations, a switch mechanism responsive to ground on either one or both sides of the line to extend the line and means operated in response to a ground on both sides for selectingthe meter corresponding to the station whose device grounds both sides of thelline.

6, In a telephone system, a two party line,-

switching device at each'station on said line, one of which is operated to ground one side of the-line, andthe other to ground both sides of theline, a meter for each of said stations, the operating circuit of the meter of said first mentioned line being normally 7 extended thereto, a switch. for extending said line, a quick and a slow acting relay re sponsive to the grounding of one side of the line to operate said switch, and a quick and a slow acting relay responsive to the grmindwit to the other of saidmeters.

ing "of both sidesof'saidline to break said' BERNARD 1); WILLI 

